Pondering CR and Live room floors

[CompEq]

I'm kicking around a few ideas and could use some help. I'm considering a build, but have to sort out a few things before I decide to go ahead or to pass. I don't have professional carpentry experience but have done room treatments and additions to existing structures. I've gotten help when necessary on these projects.

The slab is approx 17' x 35' and the studio will consist of two rooms, CR and live. Need to be fairly quiet outside (no more than I'm guessing 45 dB - the same as minimum street noise, less is better) with drums or ampeg 8x10 on 11. I figure if it's quiet enough outside with that going on, then it should be dead silent inside. Construction would be double wall with 3 sheets of 5/8" gypsum on each leaf. Room within a room built on a concrete slab above grade. The inside room will be supporting a ceiling, the outside room will be built up to the existing structure (one option). The other option is to enclose the outer structure with its own ceiling which I think would be better for isolation, but digs into precious space for interior height.

Prior to framing, does the whole concrete slab get some kind of moisture barrier or is that just under the sole plates? What type of moisture barrier should be used? I assume the sole plate should be pressure treated wood and can be attached to the concrete via construction adhesive and tapcon screws.

I would want to install wood flooring on the CR floor and possibly the live room floor as well. (not yet decided about the live room). If the CR floor is 2" 703 + 2 layers of 3/4" plywood on top of the slab, what is used around the edges between the floor and the walls? Since I've seen it discussed that maybe this isn't the way to go. I'm open to other ideas on how to lay wood floor on concrete. It is not possible to cut the slab between the live room and the CR.

[tINY]

In SoCal, this is the way everything has been built for many decades....

Typically, you use pressure treated lumber for your sill plate and attach it directly to the slab. If you haven't poured the slab yet, put j-bolts in as the concrete dries. If the slab is already there, use either some potting technique (drill and epoxy in a bolt threaded rod, etc) or use the "red head" concrete nailer with the 32 blank charges.

For "wood" floor, find an engineered flooring that clicks together and is rated for direct mounting on concrete. There is some nice bamboo that I'm looking at for putting in my slab-floor basement.

I would just paint the floor in the live room with epoxy paint (like a garage) if you are going to be setting up drums and rolling amps around in there... Get a few rugs for when you need them.



-tINY

[CompEq]

tINY,

Thanks! The slab is existing and kind of old. If I go with the potting technique, do you know what size threaded rods should go in and how deep into the concrete they need to go? What about placing the wall on top? The sole plate gets fastened down first and there are bolts sticking up. The wall has it's own "sole plate" and this gets fastened to the first sole plate that's already laid down. I have an overhead clearance issue to deal with when raising the wall, so would I drill out holes in the 2nd sole plate (the one attached to the wall) to accomodate the bolts in the 1st sole plate (the one fastened directly to the slab)?

My last room was in a mostly concrete below-grade "basement-type" space and I still have nightmares about water penetrating into the room. I had to get rid of mold, etc before moving in and don't want a repeat of that. Also, would rather err on the side of caution in this area. Although it's not a code requirement, what could be placed between the sole plate and the slab to ensure that no moisture penetrates into the sole plate?

Also, if I go with the Epoxy paint over the live room floor and later decide I want wood, do the direct-to-concrete engineered floors go just as easily over the Epoxy paint or would I have to remove the paint first?

[CompEq]

Okay, moving on to doors.

How do I calculate the STC necessary for each door when using a door-airlock-door configuration? For example since this is a logarithmic equation, two doors with an STC of 35 will not yield an STC of 70. So in order to get into the high 60's of STC, what STC would I need from each door? Each door would be built into the frame of a double-wall construction as mentioned above.

[tINY]

I think we used 5/8" for bolting down walls. You only need one sill plate, but two top plates (joints in the sill plate aren't a problem if you are attached to the slab, but you have to overlap joints in the two sticks at the top). For walls on the slab, we didn't even use pressure treated for the bottom plate as they were actually above grade.... We may have used pressure treated on exterior walls, though.

Engineered floor goes down over just about any solid, flat surface. Epoxy, stains, and even a few small voids (like from a 5/8" rod that was drilled out) are fine.



-tINY